This invention relates to magnetohydrodynamic methods and generators which supply an EMF force derived from mutual actions of conductive fluids flowing within magnetic fields. "MHD" is an abbreviation for the term magnetohydrodynamic.
More particularly, the present invention is concerned with combustion fired MHD power systems the working fluid of which consists of combustion products resulting from a combustion of chiep fuels such as coal, oil, natural gas, carbon monoxide, char and the like with an oxidant such as air. The efficiency of such MHD power systems is the greater the higher the electric conductivity of their working fluids. Conductivity, in turn, is dependent on ionization. Unfortunately, combustion temperatures of conventional combustibles are not high enough to obtain a suitable ionization of a working fluid consisting of the products of such combustion. Therefore, it has been tried to increase working fluid ionization in various manners such as by external energy, electric arc discharges, and seeding the working fluid with an alkali metal such as cesium or potassium.
Also shock waves are suitable to improve ionization since they are directional and, therefore, generate translation and dissociation terms in the direction of progress. Such means are described in British Patent specification No. 1,296,309.
Shock waves have been generated in combustors of MHD generators also by feeding them with explosives and detonating the latter periodically whereby high voltage electrical impulses in a range of 10 to 20 kilovolts could be obtained. Such MHD-generators are dealt with by Ernest H. Jager and Franz R. Thomanek in their article "Untersuchungen uber sprengstoffbetriebene MHD-Generatoren" in Vol. 25 1974 Journal of Applied Mathematics and Physics (ZAMP) pp. 47 to 54. However, explosives are relatively expensive for being used as fuels. Moreover, explosion time periods are too short for the explosive being thoroughly combusted whereby energy transformation is rendered incomplete with inevitable energy losses and low efficiency. Thus, the use of explosive fired MHD generators is, at present, economically unjustified.
The present invention is thought to be an improvement over such systems in that the principle of increasing ionization by means of shock waves is employed in connection with conventional and, thus, low cost fuels.